Refrigerating apparatus



Dec. 12, 1939. s. M. SCHWELLER REFRIGERATYING APPARATUS Original FiledMarch 25, 1933 2 Sheets-Sheet 1 I by,

Dec. 12, 1939. s. M. SCHWELLER 2,182,824

REFRIGERA TING APPARATUS Origin al Filed March 23, 1933 2 Sh t -sh t 2 II n! n 'Illllll III %N OR ATTORNEY$ at... Dec. 1 2, 1 939 UNITED STATESPATENT EOFFIC areas I v nnrmcsaa'rmc .mm'rns Application 13 Claims.

This invention relates to refrigeration and more particularly to arefrigerator compresor which operates continuously during the entireperiod of refrigeration requirement.

It is among the objects of this invention to provide a method ofrefrigerating a cabinet or the like and an apparatus for carrying outthe method, in which the cabinet and the refrigerating system are socombined that the compressor can operate continuously during the entireperiod of refrigeration requirement of the cabinet and yet in which thetemperatures desired in the cabinet may be easily and positivelymaintained without undue loss of power and without undue complications.

Further objects and advantages of the present invention will be apparentfrom the following description, reference being had to the accompanyingdrawings, wherein a preferred form of the present invention is clearlyshown.

In the drawings:

Fig. 1 is a vertical cross-sectional view of an apparatus embodyingfeatures of this invention;

Fig. 2 is a view, partly in cross-section and partly diagrammatic ofanother apparatus;

Fig. 3 is a vertical cross-sectional view of a modification form of theinvention shown in Fi 1;

Fig. 4 is a vertical cross-sectional view of a portion of a form similarto that shown in Fig. 3, but slightly modified;

Fig. 5 is a vertical cross-sectional view of on of the evaporators shownin Figs. 2, 3 and 4; and

Fig. 6 is a vertical cross-sectional view of a detail.

Refrigerating apparatus and method embodying features of my inventionare illustrated in Fig. 1, in which a cabinet,-generally designated asH! is refrigerated by a refrigeratingsystem including a compressor II, acondenser I2 and an evaporator l3 arranged in a closed cycle. Therefrigerant flows from the compressor H to the condenser l2 and fromthence, in liquid form,

through the line It and through an interchanger.

It to an".expansion valve I6. From thence the refrigerant flows throughthe evaporator i3 and returns to the compressor through the line H.Under ordinary operation, the compressor II is driven continuouslyduring the entire period of refrigeration demand by means of theelectric motor ll, which may be a constant speed alternating currentmotor of the usual type. No switch, thermostatically responsive totemperatures within the cabinet or system need be provided for startingor stopping the compressor.

March 23, 1933, Serial No. 682.304 Renewed February 23, 1939 In theembodiment shown in Fig. 1, the cabinet I0 is provided with a foodpreserving space I9 within which the evaporator I3 is placed, and with afreezing space (not shown but similar to the space 32 hereafterdescribed) within the hollow portion of the evaporator l3, preferably inthe form of ice tray sleeves, now well known in the art. The system iscontrolled to maintain the desired temperatures in the food preservingspace and the "freezing space notwithstanding the continuous operationof the compressor. The temperature in the freezing space 20 generally isdesired to be substantially below 32 F. and the temperature in the foodpreserving space 89 generally is desired to be above 32 F., andgenerally below F.; but it is to be understood, that under varyingconditions, the temperature requirements may be entirelydifferent fromthose above specified. In order to maintain the desired temperatures,the evaporated refrigerant flowing from the evaporator [3 to the com--pressor Ii is throttled by a throttle valve 2|, which throttle valve 2!is preferably of the thermostatic bulb variety, several of the detailsof which are shown in Fig. 6, and in which the thermostatic bulb 22 ismade responsive not only to the temperature of the food preserving spacel9, but also, because of its proximity to or contact with the ends ofthe ice tray sleeves, is also made responsive to the temperatures of theice freezing space.

In the operation of the apparatus shown in Fig. 1, condensed liquidrefrigerant flows through the line It to the heat interchanger l5 whereit iscooled by the returning evaporated throttled refrigerant and fromthence passes to the expansion valve I 6. From thence the refrigerantflows through the evaporator l3 simultaneously cooling the foodpreserving space I9 and the freezing space 20 and returns past thethrottling device 2| to'the'compressor ll. When the temperatures in thefood preserving space and the ice freezing space have reached asufficiently low temperature, the volatile fluid in the bulb 22 reducesthe pressure in the bellows chamber 23 (see Fig. 6) of the throttlingdevice and this causes the valve 2| to throttle the evaporatedrefrigerant returning from the evaporator iii to the compressor ll. Whentemperatures in these spaces rises, such as by the introduction of waterto be frozen in the space 20 or of warm food in space IS, the bulb 22responds and opens the throttling valve partly or wholly to increase therefrigerating capacity of the evaporator. The relative areas of theevaporator l3 and the heat 2 amass-s exchange facilities between thisevaporator and the two spaces is so arranged that under normalconditions the proper temperatures will be maintained in both spaces inresponse to actuations of the volatile fluid in the bulb 22. In themodification shown in Fig. 3, the cabinet 33 is provided with a foodpreserving space 3| and a freezing space 32. A continuously operatingcompressor 33, driven by the constant speed motor 33a, suppliesrefrigerant to a condenser 34 from whence the refrigerant flows throughthe line 35 to the exchanger 33 and from thence, in parallel flow paths.through the evaporators or branches 31 and 33, the evaporatedrefrigerantreturning through the lines or paths 33 and 43 respectivelyto the main suction line 4| and from thence back to the compressor 33 ina closed cycle. The evaporated refrigerant returning to the compressorfrom one of the evaporators,

J in this case the evaporator 31, is throttled by the throttling valve42, similar to the valve 2|, which valve 42 is made responsive in itsthrottling action to the temperature in the space 31 by means of thethermostatic bulb 43. The

5 valve 42 and bulb 43 may also be substantially of the character shownin Fig. 6.

The operation of the apparatus shown in Fig. 3'

is such that proper food preserving temperatures (above 32 F. and below50 F.) are maintained in the space 3| by the throttling action of thevalve 42, notwithstanding the continuous operation of the compressor33', while the temperatures in the freezing space 32 are allowed toassume whatever temperature the refrigerating system is capable ofmaintaining therein; but the capacity of the refrigerating system is somade that it is sufficient to maintain temperatures in the space 32below 32 F. If desired the freezing space 32 may be insulated from thefood preserving space 0 3| by means of the insulated wall 43.

In the modification shown in Fig. 4, which is somewhat similar to thatshown in Fig. 3, the compressor and condenser are substantially the sameas shown in Fig. 3, the condensed liquid refrigerant flowing through theline 33 to the exchanger 5| and from thence, in parallel flow paths, tothe evaporators or parallel branches 32 and 53. The evaporatedrefrigerant returns by means of the suction lines 34 and 35respectively, through the interchanger 5| and back to the compressor(not shown, but similar to the compressor of Fig. 3) to close the cycle.In this modification, the return branch 55 from the evaporator 33 isalso provided with a throttling valve 56, which m is similar in itsaction to the throttling valves heretofore described, but, in this case,the throttling action is made responsive to the temperatures in thefreezing space 51. In this modification, like in the modification shownin Fig. 3, the evaporated refrigerant leaving from the evaporator 52 isthrottled by means of the valve 58 responsive to the temperatures in thefood preserving compartment 53 through the medium of the thermostaticbulb 30.

B5 In the modification shown in Fig. 2, the cabinet includes a brinetank 'il in which one or more ice cream can sleeves 12 are placed sothat ice cream cans may be introduced by the removal of the lids 13. Thebrine in the tank II is cooled 70 by means of evaporator 14 which ispart of the refrigerating system including the continuously operatingcompressor 15 and condenser 13. As is the case with the modificationshown in Figs. 1,

3 and 4, the compressor I5 may be driven by the constant speed electricmotor 11 which may be actuated by direct or alternating current in thewell known manner. In this case. the evaporated refrigerant returningfrom the evaporator 14 to the compressor 13 is throttled by means of avalve i8 responsive to the temperatures of the brine 6 through themedium of the thermostatic bulb 13,. As is the case with all of thethrottling valves heretofore described and shown in Figs. 1, 3 and 4,the valve 13 is made substantially as shown in Fig. 8. 10

The evaporators shown in Figs. 2, 3 and 4, may be of the well knownflooded type having a float controlled inlet valve, the floatmaintaining a substantially constant level of refrigerant within theevaporator. To this end these evaporators 15 may be provided with aheader 33, see Fig. 5, which contain the inlet valve 3| and the floatcontrol therefor 32. The liquid refrigerant is fed to downwardlydirected heat exchangers 33,

which may be circular or plate-like ducts into which the liquidrefrigerant flows and from which the evaporated refrigerant rises. Theevaporated refrigerant leaves through the funnel 34 and returns to thecompressor as heretofore described.

The throttling valves heretofore described may 23 be similar to thatshown in Fig. 6. In this instance the line returning from the evaporatorenters at 33 and leaves through the line 33 to the compressor. Athrottling valve 24 is connected to the rod 33a which is sealed againstthe escape of refrigerant by the bellows 31. The thermostatic bulb 33creates pressures in the chamber 23 which, acting on the bellows 33varies the throttling action of the valve 24 in accordance I with thetemperatures acting on the bulb 33. The so responsiveness of the valveto the cabinet temperatures aflecting the bulb 83 may be varied, so thatthe system may be caused to maintain different temperatures in thecompartment wherein the bulb 33 is placed. To this end the spring 33abuts against the adjustable screw 3| having a pointer handle 32. Byreturning the handle 32, with which a numbered temperature indicatordial, not shown, may be associated, the tension of the spring 33 may bevaried, and this varies the responsiveness of the valve to thetemperatures affecting the bulb 33.

A manually operated switch may be provided for stopping the compressorfor repairs, or, very infrequently, for defrosting. This switch need notbe operated to maintain cabinet temperatures during the period ofrefrigeration demand.

The throttling action of the valves heretofore described reduces theload on the compressor, so that, when the valves are nearly closed, thecompressor practically idles and consumes practically no power. Byeliminating the stopping and starting problems usual with a thermostaticswitch, efficiency is enhanced and cost of production is reduced. 00

While the form of embodiment of the invention as herein disclosedconstitutes a preferred form, it is to be understood that other formsmight be adopted, all coming within the scope of the claims whichfollow. 5

What is claimed is as follows:

1. The method of refrigeration of a cabinet or the like by means of asystem having a compressor, condenser and evaporator in a closed cycle,which comprises operating the compressor continuously during the entireperiod of refrigeration requirement of said cabinet, throttling thereturn of evaporated refrigerant from said evaporator to said compressorin accordance with cabinet temperatures and cooling condensedrefrigerant before entrance in said evaporator by means of evaporatedrefrigerant after it has been throttled.

2. A refrigerating apparatus comprising a cabinet or the like, arefrigerating system for refrigerating said cabinet including acompressor, condenser and evaporator in a closed cycle, said compressoroperating continuously during the en'- tire period of refrigerationrequirement of said cabinet, means for throttling the return ofevaporated refrigerant from said evaporator to said compressor inaccordance with cabinet temperatures, and means for cooling condensedrefrigerant before entrance into said evaporator by evaporatedrefrigerant after it has been throttled.

,3'. A refrigerating apparatus comprising a cabinet having a freezingspace and a food preserving space, a refrigerating system forrefrigerating said cabinet including a compressor, condenser and twoevaporators in which the refrigerant flows in a closed cycle and inwhich said evaporators form parallel paths in said cycle between saidcondenserrand compressor, said compressor operating continuously duringthe entire period of refrigeration demand of said cabinet, one of saidevaporators cooling said freezing space and the other of saidevaporators cooling said food preserving space, means for throttling thereturn of evaporated refrigerant from one of said evaporators to saidcompressor in accordance .with temperatures in one of said spaces, and

means for cooling condensed refrigerant before entrance into one of saidevaporators by means of evaporated refrigerant after it has beenthrottled.

4. The method of refrigeration of a cabinet having a freezing space tobe maintained below 32 F. and a food preserving space to be maintainedabove 32 F. by means of a system having a compressor, condenser andevaporators in a closed cycle and said freezing space being an insulatedspace within said food preserving space, which method comprisesoperating the compressor continuously during the entire period ofrefrigeration requirement of said cabinet, cooling said freezing spaceand said food preserving space by means of said evaporators by operatingthem at difierent intensities, and throttling the return of evaporatedrefrigerant from one of said evaporators to said compressor in accord-.

ance with temperatures in said freezing space and food preserving space.

5. The method of refrigeration of a cabinet having a freezing space tobe maintained below 32 F. and a food preserving space to be maintainedabove 32 F. by means of a system having acompressor, condenser and twoevaporators in which the refrigerant flows in a closed cycle and inwhich said evaporators form parallel paths in said cycle between saidcondenser and compressor and said freezing space being an insulatedspace within said food preserving space, which method comprisesoperating the compressor continuously during the entire period ofrefrigeration requirement of said cabinet, cooling said freezing spaceby means of one evaporator and cooling said food preserving space by theother of said evaporators.

6. The method of refrigeration of a cabinet having a freezing space tobe maintained below 32 F. and a food preserving space to be maintainedabove 32 F. by means of a. system having a single compressor, condenserand two evaporatorsin which the refrigerant flows in a closed cycle andin which said evaporators form paralinsulatedspace within said-foodpreserving space,

which method comprises, operating the compressor continuously during theentire period of refrigeration' requirement of said cabinet, coolingsaid freezing space by means of one evaporator and cooling said foodpreserving space by the other of said evaporators, and throttling thereturn of evaporated refrigerant from one of said evaporators.

7. The method of refrigeration of a cabinet having a freezing space tobe maintained below 32 F. and a food preserving space to be maintainedabove 32 F. by means of a system having a single compressor, condenserand two evaporators in which the refrigerant flows in a closed cycle andin which said evaporators form parallel paths in said cycle between saidcondenser and compressor and said freezing space being an insulatedspacewithin said food preserving space, which method comprises operating thecompressor continuously during the entire period of refrigerationrequirement of said cabinet, cooling said freezing space by means of oneevaporator and cooling said food preserving space by the other of saidevaporators, and throttling the return of evaporated refrigerant fromeach of said evaporators.

8. The method of refrigeration of a cabinet having a freezing space tobe maintained below 32 F. and a food preserving space to be maintainedabove 32 F. by means of a system having a compressor, condenser andevaporator in a closed cycle and said freezing space being an insulatedspace within said food preserving space, which method comprisesoperating the compressor continuously during the entire period ofrefrigeration requirement of said cabinet, cooling said freezing spaceto a temperature below 32 F. and said food preserving space to atemperature above 32 F. by means of said evaporator,and throttling thereturn of evaporated refrigerant from said evaporator to said compressorin accordance with temperatures in said I freezing space and foodpreserving space.

ferent temperaturesv by means of said evaporators,

and throttling the return of'evaporated refrigerant from saidevaporators to said compressor in accordance with temperatures in saidcompartments.

10. The method of refrigerating separate spaces by means of arefrigerating system having a compressor-condenser unit and a pluralityof evaporators connected in closed circuit relation which comprises,operating the compressorcondenser unit continuously during the entireperiod of refrigeration requirement of the spaces, cooling one space bymeans of one of said plurality of evaporators and cooling the otherspace by means of another of said plurality of evaporators, andthrottling the return of evaporated refrigerant from said one evaporatorto said compressor-condenser unit in accordance with the temperature ofone of said spaces while permitting unrestricted return of evaporatedrefrigerant from said another evaporator to 'said compressor-condenserunit to operate the evaporators at different intensities relative to oneanother.

11. The method of refrigerating separate spaces by means of arefrigerating system having a compressorcondenser unit and a pluralityof evaporators connected in closed circuit relation which comprises,operating the compressorcondenser unit continuously during the entireperiod of refrigeration requirement of the spaces, cooling one space bymeans of one of said plurality of evaporators and cooling the otherspace by means of another of said plurality of evaporators, throttlingthe return of evaporated refrigerant from said one evaporator to saidcompressor-condenser unit in accordance with the temperature of one ofsaid spaces while permitting unrestricted return of evaporatedrefrigerant from said another evaporator to said compressor-condenserunit to operate the evaporators at different intensities relative to oneanother, and transferring heat from refrigerant supplied to saidevaporators to the refrigerant returning to said compressor-condenserunit.

12. The method of refrigerating separate spaces by means of arefrigerating system having a compressor-condenser unit and a pluralityof evaporators connected in closed circuit relation which comprises,operating the compressorcondenser unit continuously during the entireperiod of refrigeration requirement of the spaces, cooling one space bymeans of one of said plurality of evaporators and cooling the otherspace by means of another of said plurality of ture of the space cooledthereby to operate the evaporators at diflerent intensities relative toone another.

13. The method of refrigerating separate spaces by means of arefrigerating system having a compressor-condenser unit and a pluralityof evaporators connected in closed circuit relation which comprises,operating the compressorcondenser unit continuously during the entireperiod of refrigeration requirement of the spaces, cooling one space bymeans of one of said plurality of evaporators and cooling the otherspace by means of another of said plurality of evaporators, throttlingthe return of evaporated refrigerant from said one evaporator to saidcompressor-condenser unit in accordance with the temperature of thespace cooled thereby, throttling the return of evaporated refrigerantfrom said another evaporator to said compressorcondenser unit inaccordance with the tempera ture of the space cooled thereby to operatethe evaporators at different intensities relative to one another, andtransferring heat from refrigerant supplied to said evaporators to therefrigerant returning to said compressor-condenser unit.

SYLVES'IER M. SCHWELLER.

